Method of making underbeveled printing plate



April 26, 1960 T. J. mum 2, 3

METHOD OF MAKING UNDERBEVELED PRINTING PLATE med Oct. 30, 1957 16ilnn/urlnllnllnumln BY mwwwgw United States v Patent i METHOD OF MAKINGUNDERBEVELED PRINTING PLATE Thaddeus J. Malicki, Homewood, Ill.,assignor to R. R.

Dounelley & Sons Company, a corporation of Delaware Application October30, 1957, Serial No. 693,350

4 Claims. (Cl. 101-4011) The present invention pertains to printingplates for cylinder presses and more particularly to underbeveled pressplates and a method for their manufacture.

In certain rotary printing presses, the printing plates are secured tothe plate cylinder by means of plate clips which are positioned in thecylinder and engage beveled sides of the plate to hold it in properposition. In order to obtain adequate engagement between the clip andthe plate, it is imperative that a suitable clip seat be supplied toaccommodate the holding device.

Where the bevel at the side of a plate extends to the top surface, themanufacture of the plate presents no problem; but where the bevel iswholly below the top surface, so as to be undercut, the machiningoperation requires special machine tools and the time of skilledoperators to make the plates.

In accordance with the present invention, a plate with underbeveledsides is made in two partsa backing plate and an electrotype plate; andthe bevel is formed in the upper margins of the backing plate before itis joined to the electrotype plate. Thus, the two parts of the laminatedplate cooperate to form the undercut grooves, or clip seats.

Since the beveling of a plate edge is a simple operation which may beperformed in a number of different ways, the production of the grooveslot is greatly simplified by beveling the backing plate, forming it tothe curvature of the electrotype plate, and securing the backing plateto the electrotype plate to form a laminated printing plate.

It is, therefore, a primary object of this invention to provide animproved method of manufacture to produce a printing plate with anundercut clip seat.

It is a further object of this invention to provide a printing plate oflaminated construction having an undercut groove in the curved endthereof.

These and other objects of the present invention will be apparent to oneskilled in the art from the following detailed description when taken inconjunction with the drawings, wherein:

Fig. 1 is a perspective view of an electrotype plate;

Fig. 2 is a perspective view of a backing plate blank;

Fig. 3 is a perspective view of the backing plate which has had itsedges beveled;

Fig. 4 is a perspective view of a beveled backing plate which has beenformed to conform to the curvature of the electrotype plate;

Fig. 5 is a perspective view of an assembled laminated printing plate;and

Fig. 6 is an enlarged sectional view taken along the lines 66 in Fig. 5which illustrates the clip seat formed by the beveled portion of thebacking plate in cooperation with the electrotype plate.

Referring now to the drawings, an electrotype or other printing plate,indicated generally at 10, is arcuate as seen in Fig. 1, so as to beconcentric with the surface of a plate cylinder of a rotary printingpress. The printing character or intelligence is formed on the convexsurface of the arcuate plate 10. A backing plate 11 is of suchdimensions that it may be given the same curvature as the electrotype'ice plate 10 and its entire convex surface adhered to the entire underor concave surface thereof.

After the backing plate 11 is cut to the proper dimensions, the sides 12and 13 corresponding to the curved sides of the electrotype plate 10 arebeveled along their upper edges as shown at 14 and 15 in Fig. 3. Thebeveling may be done on any standard milling machine or in any othersuitable way.

After the edges 12 and 13 of the backing plate 11 have been beveled inany suitable manner, the plate is placed in a forming die to give it thesame curvature as the electrotype plate 10. An alternate method ofmanufacturing the backing plate 11 is to cast it in its curved form toconform with the curvature of the electrotype plate 10 and to then formthe bevels thereon as described above for the flat'p ate. Since,however, the milling of the fiat plate is somewhat easier, the firstmethod is preferred.

After the bevels have been formed, the backing plate is positionedbeneath the electrotype plate with the convex or outer curved surface ofthe backing plate in contact with the concave or inner curved surface ofthe electrotype plate, and they are adhered together by welding,brazing, or any other suitable means, such as a layer of adhesive 16, toform a laminated printing plate.

In summary, the new and improved laminated printing plate of thisinvention is manufactured by forming a backing plate of any suitablematerial to the conformation of an electrotype plate, beveling the topedges of the curved sides of the backing plate either before or afterthe backing plate is conformed to the curvature of the electrotypeplate, and finally securing the backing plate to the electrotype platewith the beveled portion of the backing plate toward the back of theelectrotype plate and the corresponding marginal portions of theelectrotype plate over hanging the bevels so that the two platescooperate to form an underbeveled groove which provides a clip seat.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations are to be understoodtherefrom, as modifications will be obvious to those skilled in the art.

1. A method of making an underbeveled printing plate for the platecylinder of a rotary printing press comprising the steps of: providingan arcuate printing plate with a printing face on its convex surface;providing an arcuate backing plate of substantially the same size assaid printing plate and of a radius of curvature corresponding to thatof the printing plate; beveling two opposite edges of the convex surfaceof said backing plate to reduce the dimension between said edges so thatit is slightly less than the corresponding dimension of the printingplate; and thereafter adhering the convex surface of the backing plateto the concave surface of the printing plate with each beveled edge ofthe backing plate spaced slightly inwardly from the corresponding edgeof the printing plate so that the marginal portions of the printingplate overhang the bevels, whereby the beveled edges and saidoverhanging marginal portions cooperate to provide underbeveled platemargins.

2. A method of making an underbeveled printing plate for the platecylinder of a rotary printing press comprising the steps of: providingan arcuate backing plate having a predetermined inside radius ofcurvature determined by the radius of the plate cylinder; beveling twoopposite edges of the convex outside surface of said backing plate; andthereafter adhering the concave back surface of an arcuate printingplate to the outside surface of the backing plate with opposite marginalportions of the printing plate overhanging the bevels on the backingplate, whereby the beveled edges and said overhanging marginal portionscooperate to provide underbeveled plate margins.

3. A method of making an underbeveled arcuate printing plate for a platecylinder of a rotary printing press museum comprising the steps of:forming an arcuate electrotype a portion of one major surface of saidbacking plate to form beveled edges thereon and reduce the dimension between said edges so that it is slightly less than the correspondingdimension of the printing plate; curving said backing plate to provideit with an outer convex surface concentric with that of the printingplate, and with said reduced dimension in said convex surface; andthereafter adhering the convex surface of said plate to the concavesurface of the electrotype plate with opposite marginal portions of theelectrotype plate overhanging the bevels, whereby the beveled edges andsaid overhanging marginal portions cooperate to provide underbeveledplate margins.

4. A method of making an underbeveled printing plate for the cylinder ofa rotary printing press comprising the steps of: providing an arcuateprinting plate. with a print ing face on its convex surface; forming anarcuate backing plate having a radius of curvature corresponding to thatof the printing plate and of substantially the same size as the printingplate, said backing plate being formed with two opposite edges of itsconvex surface bevelled so that the dimension between said edges isslightly less than the corresponding dimension of the printing plate;and thereafter adhering the convex surface of the backing plate to theconcave surface of the printing plate with opposite marginal portionsoverhanging the bevels, whereby the beveled edges and said overhangingmarginal portions c0- operate to provide underbeveled plate margins.

References Cited in the. file of this patent UNITED STATES PATENTS568,390 Whitcomb et a1. Sept. 29, 1896 2,383,080 Reilly et al Aug. 21,1945 2,531,375 Delegard 'et a1. 'Nov. 21, 1950 2,558,269 Reilly June 26,1951 2,841,082 Fitzpatrick July 1, 1958 FOREIGN PATENTS 520,501 CanadaIan. 10, 1956' Great Britain Sept. 27, 1921

